Composite closure cap and method of making same



' Sept. 19, 1939. J.KRONMAN 2,173,449

COMPOSITE CLOSURE CAP AND METHOD OF MAKING SAME Filed March 9, 1934 Joe! lfroimza INVE 0R Patented Sept. 19, 1939;

UNITED STATES PATENT OFFICE COMPOSITE CLOSURE CAP AND IMETHOD OF MAKING SAME Joel Kronrnan, New York,- N. Y.. assignor to Victor Metal Products Corporation, Brooklyn, N. Y., a corporation of New York Application March 9, 1934, Serial No. 714,797

2 Claims. (Cl. 215-43) high percentage of alcohol. It'has been. found that caps made of such plastic material are acted upon by the alcoholic contents of the bottle such as liquor, perfume, medicines or the like. In cases where the cap is made of a phenolic resin, the result is an unpleasant phenolic odor. Caps of such plastic material, however, have distinct advantages in that they are moldable into ,a great variety of forms and designs. They may also be made in a variety of different colors and are durable, not being likely to become distorted under repeated use, though being somewhat brittle, they may chip or crack.

My invention therefore contemplates the provision of a composite molded cap having all the advantages of a molded cap, but preventing the,

contents of a bottle which is sealed by the cap from coming into contact with themoldable or plastic material thereof.

My invention further contemplates the provision of a composite cap having the inner part thereof made of metal and having the outer part thereof made of plastic material, said parts being firmly and permanently united against separa- Fig. 1 is a vertical section of a pair of molding dies by means of which the cap may be made; the metallic portion of the cap being shown as a threaded blank screwed on to the threaded male die, and the plastic material being shown in place in the-female. die.

Fig. 2 is a similar view of the same, showing the finished cap formed with the inner threaded metallic part and the outer plastic material molded aboutand united to the metallic part.

Fig. 3 is a similar fragmentary view of the threaded neck portion of a bottle showing the finished cap of Fig. 2 in place on the bottle,

Fig. 4 isa view similar to Fig. 1 showing, however, an unthreaded metallic liner blank. I

Fig. 5 is a view similar to Fig. 2 showing the unthreaded metallic blank forced by pressure into threaded form to produce a cap similar to that of Fig. 2.

- Fig. 6 is a view similar to Fig. 3 showing the cap of Fig. 5 in place on a bottle.

Fig. '7 is a view of the dies and blanks similar to Figs. 1 and 4, the metallic portion of the cap,

however; being shown with a partly open end and 1 Y with a cork or similar washer inserted thereunder and held in place on the male die prior to the pressure operation of uniting the parts .to form the cap.

Fig. 8 is a view similar to Figs. 2 and 5, of the formed and finished cap produced by the dies of Fig. 7.

Fig. 9 is a fragmentary view similar to Figs. 3 and 6, of the finished cap produced by the dies of Figs. 7 and 8 and shown in placeon a bottle.

Fig. 10 is a similar fragmentary view of a modified form of the same showing a resilient washer arranged between the metallic portion of the cap and themolded portion thereof.

- Fig. 11 is a perspective view of a finished cap, partly in section.

In the practical embodiment of my invention which I have shown by way of example, my improved cap may be made and my improved process carried out by mechanism similar to that heretofore customarily used in the manufacture of caps of plastic material.

As shown, said mechanism comprises a male die as l0 terminating in a reduced threaded portion ll adapted to hold the metal portion of the cap preparatory to the pressure operation. The

thread on said threaded portion corresponds to v the thread on the bottle with which the cap is to be used. The male die It]. may be suitably supported and guided as for example by a stationary part l2. The female die I3 is formed with a mold or cavity l4 into which is inserted the desired quantity of the plastic material I 5 in plastic form. Both the male and female dies are heated in the customary manner, as for example, by receiving heat from a heated platen on which the dies rest.

In the form of my invention shown in Figs. 1, 2 and 3, the metallic tubular blank l6 forming the inner lining of the cap is provided with a closed end I1 and with apreformed threaded cylindrical portion l8, which is formed with its threads before it is arranged on the portion ll of the die.

This is particularly desirable where the metal used is comparatively hard, such as aluminum or other suitable and comparatively hard metal.

The dies l0 and I3 are brought together by suitable mechanism well known in the art and therefore not necessary to be illustrated or described in detail. When the male die or plunger I is forced into the cavity l4, pressure and heat are applied to the plastic material IE to force said material inwardly into the threads of the metallic part l6 and outwardly to fill up the die cavity, into the form shown in Figs. 2 and 3. When the dies are now separated to the position of Fig. 1, the finished cap is withdrawn from the cavity l4 and may be readily removed from the die by unscrewing it. It will be understood that the die or mold cavity l4 may be made in any desired shape and that the plastic material [5 may be given any desired color and surface ornamentation l9, (Fig. 11) to provide a finished cap resembling in appearance any of the phenolic resin or other molded caps now customarily used.

It will further be understood that owing to the pressure applied by the dies, the molded material is forced into intimate contact with the metallic part l6, thereby joining the molded-and metallic parts permanently and inseparably. The metallic part reinforces the molded part of the cap, and makes it practically unbreakable under ordinary stresses. It also reinforces the molded part of the cap against chipping, thereby preventing any particles of the moldable material from chipping off and falling into the bottle with which the cap may be used. As shown in Fig. 3, the metallic part further prevents access of the contents of the bottle to the molded part of the cap and thereby prevents any chemical or other action therebetween or the formation of gases or the release of unpleasant odors and the contamination of the contents. t

In the form of my invention'shown in Fig. 4, the metallic part or blank 20 takes the form of a cylindrical tube closed at one end by the end wall 2|. The part 20 in this case is preferably made of comparatively soft metal such as tin, or tin and lead alloys, or lead alloys of various ln'nds, or even lead. The innermost diameter of the closed tube 20 conforms to the greatest outer diameter of the threaded part vl I of the male die, so that said tube may be readily forced on to the part II and held thereon by friction. When the male die and female die are brought together and the material I5 extruded, the consequent pressure upon the plastic material forces the wall of the comparatively soft metal tube into'intimate contact with the die part I I throughout and thereby forms the internal threads on the metallic part 20 corresponding to the threads on the die part II. The finished cap shown in section in Fig. 6 and produced as just described, is similar to the cap of Fig. 3 excepting that the metallic portion is softer and is thereby readily threaded under the pressure of the extruding operation, so that the blank need not be preformed with screw threads thereon.

Referring now to Figs. 7, 8 and 10, the metallic part 25 there shown is preferably of comparatively soft metal but is provided with an opening .as 26 in its end wall 21. Said metallic part 25 is from the stationary spring fingers 29 and is forced against the plastic material l5 during the heating and pressure applying operation as shown in Fig. 8. At the same time, the pressure conforms the cylindrical wall of the metallic part 25 to the threads of the die and causes the parts to be firmly pressed together and securely held. Upon the withdrawal of themale die and the removal of the finished cap therefrom, the washer 28 being resilient, and the pressure thereon being released, it extends into the opening 26, the peripheral part of said washer, however, tending to remain compressed by the comparatively rigid annular end 'wall 21 of the metallic part of the cap. When the finished cap 30 (Fig. 9) is arranged on the bottle, the end 3i of the bottle compresses the disc 28 at a point spaced from the wall 21 and thereby formsan adequate seal while'loss orjseparation of the disc is prevented by the'wall 21.

As shown in Fig. 10, the openingZG may be dispensed with, and the disc 28 may be compressed throughout its peripheral edge by the, end wall 2| of the metallic portion of the cap. Said end wall may be made thinner than the cylindrical walls if desired, but in any case; being made of soft metal, it is unable to withstand the expansion of the resilient washer or disc 28, which bends said end wall when the pressure of the die thereon is released into the position of Fig. 10, the peripheral portion of the end wall, however, being reinforced by the threaded part, remaining rigid. The end wall 2| and the disc 28 are both compressed by the bottle edge when the cap is-in use, as is clearly shown in Fig. 10.

It will be understood that regardless of the hardness or softness of the metal lining used in any of the forms of my improved cap, said lining is of sufficient strength and thickness to withstand ordinary use, as when the cap is repeatedly screwed on to the bottle .neck and repeatedly unscrewed therefrom.

It will further be seen that I have provided simple and efiicient method for the manufacture of a composite cap formed partly of metal and partly of moldable material and adapted to be carried out economically and efficiently.

While I have shown and described certain specific embodiments of my invention, it will be understood that I do not desire to limit myself thereto but intend to claim my invention as broadly as may be permitted'by the state of the prior art and the scope of the appended claims.

I claim:

1. A unitary cap comprising a molded part of resinous material having a closed top, a threaded soft metal lining permanently self-held to the molded part for movement therewith as a unit and of sufficient strength to withstand screwing of the cap on a bottle and the unscrewing thereof and having an end wall and a resilient cork washer interposed and fixed between the closed top of the molded part and the end wall of the lining.

2. A cap comprising a member of moldable resinous material having a tubular wall and an end closing wall, a metallic lining in forced intimate and permanent contact with the tubular wall, said lining having a threaded tubular wall terminating in an imperforate end wall at substantially right angles to the threaded wall, and a flat resilient cork disc interposed and fixed between the end wall of the lining and the closingwall of the member. JOEL KRONMAN. 

